Basically as the title suggests

make it so SRMs STs fire their missiles continuously one by one as long as you hold the trigger with the tube count improving the fire rate

So for example

SRM2 ST would fire twice per second
SRM4 ST would fire thrice per second
SRM6 ST would fire four times per second

bear in mind theses values are made the $*ù! up and merely here to make a point

IMO it would make it possible to have MLRS-like mechs with this without overheating the hell out of any mech attempting it